Web supply mechanism



J1me 1960 v c. E. F. WILLIS 2,941,742

WEB SUPPLY MECHANISM Filed July 13, 1956 3 Sheets-Sheet l Inventor;

M MHWZM 405443 Y By.

A Home y S zamww June 21, 1960 c. E. F. WILLIS WEB SUPPLY MECHANISM 3Sheets-Sheet 2 Filed July 15, 1956 wwmqw u A ltor 'n eyS Jufi Q1, 1960c. E. F. WILLIS 2,941,742

WEB SUPPLY MECHANISM Filed July 13, 1956 3 Sheets-Sheet 3 Inventor:

Attorneys United States WEB SUPPLY MECHANISM Claude Edward FrederickWillis, Norbury, London, England, assignor to R. W. 'Crabtree & SonsLimited, Leeds, England This invention relates to web supply mechanismfor printing and other web consuming machines. The invention is moreparticularly concerned with such mechanism in which the running websupply is drawn from a running roll on a support which supports at leastone other roll forming a replacement roll which can be speeded up toenable its web to be joined, while the web consuming machine is running,to the running web which is then severed.

It is usual for the support to be moved to bring the two rolls into theproper relationship to enable the running web and the periphery of thereplacement roll to assume the position in which they can be pressedagainst one another to be joined. It is common to control the tension inthe running web by what can be termed a periphera brake to engage theperiphery of the running roll: when however the support is moved toefiect a web renewing operation, the running roll passes out of controlof the peripheral brake: it is therefore usual to provide another braketo maintain at this time the tension in the running web through its coreor centre by what may be termed a core brake.

It is the main object of this invention to provide such improvements inthis class of mechanism as will result 'in improved operating conditionsand simplification in construction.

The invention consists ill providing an electromagnetically operatedbrake at each roll position and in providing circuit control means forthe brakes by which the tension control can be transferred from theperipheral brake to the electromagnetically operated brake to enable thevarious requirements which are involved in effecting a web renewingoperation, to be met in a simple fashion.

The invention is illustrated in the accompanying drawings; in thesedrawings:

atent Figure 1 is an end elevation of a web supply mechanism;

Figure 2 is a diagrammatic view showing an electrical control mechanismfor electromagnetically operated brakes;

Figure 3 is a sectional side elevation;

Figure 4 is an end elevation showing the arrangement of theelectromagnetically operated brakes.

Referring to the drawings, the mechanism comprises a rotatable supportconsisting of spaced spiders each having arms 1, 2, 3 carried by aspindle 4 which can be turned by a motor M (Fig. i). The arms carrythree rolls 5, 6, 7 which, by turning the support, can be broughtsuccessively into a normal running position corresponding to thatoccupied by the roll 6 as shown. In the setting of the parts shown inFigure 1, the running web W is passing from the roll 5, the supporthaving already been turned to carry the roll 5 from the normal runningposition (now occupied by the roll 6) to the web-renewing position inwhich the web W passes in a position adjacent the periphery of the roll6 so that the Web and the roll 6 are positioned for the renewingoperation. The roll 7 is a freshly loaded roll which will in its turn bemoved into running and renewing position.

The roll 5 when in its running position is engaged at its periphery byendless belts 8 passing over pulleys 9, 10, 11 of which the pulley 11 iscarried by a frame 12 which can swing about the axis of the pulley 10while the pulley s is driven by the printing machine and normallyexercise a small drag on the running roll to tension its web. The beltsare controlled as to the degree of wrap about the roll to maintain asensible constant tension in the web W. The belt frame 12 and thereforethe belts 8 can swing so as to follow the decrease in the diameter ofthe running roll 5, when in normal running position.

The apparatus also has a mechanism to prepare the parts for the renewingoperation, i.e. to raise the belt frame 12, to turn the arms 1, 2, 3 tobring the at present stationary replacement roll 6 (already preparedwith adhesive at its periphery) into a renewing position below theraised belts S, to lower the belt frame to cause the belts 8 to engageand speed up the replacement roll 6 to a peripheral speed equal to thespeed of the web W still running from the running roll 5 which has nowbeen moved from its normal running position to the renewing positionshown in Figure l. A renewing assembly is provided comprising a brush 13to deflect the running web W against the periphery of the replacementroll 6 and a knife 14 to sever the running web W, the brush and knifebeing carried by a swinging arm assembly 15. The mechanism so farreferred to is well known so that further description is believed to beunnecessary.

When the belts 8 are raised clear of the running roll 5 to enable therolls to be moved in readiness for a web renewing operation, the beltsare no longer able to exercise control in the tension in the running webW. This invention provides a simple and easily controlled mechanism toenable tension control to be transferred to the core of the roll at atime when the belts 3, are raised.

This is effected by providing on the support at each of the rollpositions on it an electromagnetically controlled friction brakeindicated generally at B the coil or winding of which is controlled by afloating roller 16 which runs in a loop in the web W: this floatingroller 16 also controls in any known manner the movement of the frame 12for applying the web-tension control through the belts 8 when therunning roll is in its normal position. The floating roller 16 iscarried by an arm 17 to operate two switches 18, 1- (see Figure 2)having in a known manner spaced pairs of contacts 2%, 21. If the tensionin the web increases, the switches are operated to close one of thepairs of contactsof each switch, and if the tension decreases, theswitches are operated to close the other pair of contacts, the gapbetween the pairs of contacts being sufficient to enable the'web tensionto fluctuate to a small extent without varying the brake action appliedtothe roll.

The switch 18 is in the control circuit of an electric motor M tocontrol the belt frame 12. Now for the purpose of this invention theswitch 19 is inthe control circuit of the windings of the magnetscontrolling the core brakes B. It is necessary that the rolls shall notbe subjected to the braking action of the belts 8 and of the brake B atthe same time: it is very desirable that at all times the braking actionon the rolls while they are active shall depend on the actualrequirements of the web and not on a preset braking action: it is alsonecessary that the running roll shall be subjected to the control of thecore brake B throughout its movement from the normal running position(occupied by the roll 6 as shown) to the renewing and expiring position(occupied by the roller 5 as shown): it is desirable too that when theweb supply has been transferred from the expiring roll 5 to thereplacement roll 6, the core brake B for the roll 5 shall be fullyapplied when the knife 14 has cut the web passing from that roll so asthereby to bring the roll 5 quickly to a standstill to preventthe'remaining paper from becoming unravelled: it is further requiredthat when the web feed has been transferred to the replacement roll (theroll as shown at 6), the tension control on that roll shall be appliedby the belts 8.

The use of electromagnetically operated brakes enables these variousrequirements to be satisfied in a very simple manner avoiding suchcomplication which would arise if mechanically operated brakes wereused.

Thus, referring mainly to Figure 2, each electromagnet for operating thecore brakes B comprises energising coils 22 the supply lines of whichare connected to brushes 23, on the support engaging a slip ring 25 andto brushes 24 on the support and which are serially engageable with slipring segments 26, 27 and 28. One slip ring 25 is continuous and isconnected to one side P of a direct current power supply and the slipring segments 26, 27 and 28 are separated angularly and are variouslyconnected to the other side P of the power supply to enable thedifferent requirements to be met.

The energisation of the electromagnets is controlled by a rheostat R thewiper 29 of which is connected to a .motor M itself controlled by thedrop roller switch 19:

this rheostat is normally inactive but when a renewing operation is tobe carried out, it is connected across the power supply lines P P by aswitch 32, which can, in the usual way, be operated by an operator orautomatically by a response to the reduction in the diameter of therunning roll. At this time the motor M is energised by operation of theswitch 18 concomitantly with operation of the switch 19 to raise the.belts 3 clear of the roll in running position and a switch 31 isoperated automatically by this movement to connect the segment '26 tothe wiper 29 of the rheostat: the tension control of the web W is nowexercised by the drop roller 16 operating through the motor M to controlthe wiper 29 of the rheostat R and thence via the appropriate segment26, the energisation of the winding 22 of the core brake B of the rollin running position; this control continues so long as the relevantbrush 24 is in engagement with the segment 26.

When new the roll support is turned to move the running roll from thenormal running position to the renewing position, the brush 24 connectedto the winding 22 of the renewal roll (i.e. the roll 6 as shown) mustpass on to the segment 26 so as itself to be controlled later by itsfriction core brake B. It is however necessary at this time for therenewal roll 6 to be free so that it can be rotated from rest by thebelts 8 when they are lowered again into position. It is thereforenecessary to disconnect the segment 26 from the power supply: at thesame time it is still necessary to maintain the core brake B on the roll5 which is still the running roll although it is now moving to thereplacement position shown by the roll 5.

To achieve these results, the switch 31 is changed over by the movementof the roll support from the line 33 to connect the segment 26 to a line34 to connect the segment 27 which is now engaged by the brush 24 of thewinding 22 of the core brake of the running roll 5. The tension controlexerted by the core brake B is thus maintained on the running roll whileit is moving to and is in the renewing position.

In the renewing operation, the brush and knife assembly 15 move down tothe position shown in Figure 1. So far as the present invention isconcerned, this operation can be effected either by the operator orautomatically in any of the ways at present in use. At the conclusion ofthe operation when the knife 14 has cut the web passing from the expiredroll, the assembly is moved up to an inoperative position: the line 34connected to the segment 27 is transferred from the rheostat wiper 29direct to the line P by a switch 35 so that the appropriate core brake Bis fully applied by the energisation of its actuating winding 22 to holdthe now expired roll from spinning.

The segment 28 is arranged to be engaged by the brushes 24- of thevarious roll positions as they successively pass to the loading positionoccupied by the roll 7 as seen in Figure 1. This segment is connectedvia a line 36 to the supply line I so that under control of a switch 37the windings 22 for the electromagnets operating the vmious core brakesB can be applied and released as found necessary by the operator.

It will be clear now the use of electromagnetically operated core brakesenables the various requirements to be met in a simple fashion: thearrangement moreover enables the transition of tension control from thebelts 8 to the core brakes B to be eifected without shock to the web.

As a matter of construction reference will be made to Figures 3 and 4which show the mechanical arrangement of the support. One of the spidershas, at each roll position, a rotatable bung M) to enter one end of thecore 41 of a roll: the other spider has ateach roll position acorresponding bung 43 to enter the core at the other end and this bungis fast with a ring 44 carrying studs 45 on which is slidably mounted aferrous disc 46. The face of this disc rotates over a friction pad 4'7in an annular cup 48 which is fast with a ring 49 secured to the spiderthe disc 46 and the pad 47 constituting the friction core brake B.Housed in the cup are the coils 22 which are connected to the brushes23, 24 so that when, as has been described, power is applied across thebrushes, the coils 22 are energised and by magnetic action draw the disc46 against the pad 47: this sets up part-rings carried by an insulatingring 51 within a cage 52, disposed about a hub 53 of one of the spidersand the brushes 23, 24- of each roll position are carried by a plate 54secured to that hub.

The rolls are prepared (usually in their loading position) for therenewing operation by applying adhesive to their peripheries, therunning web W when pressed by the brush 13 against the roll adhering bythe adhesive to the end of the web of the new roll and so drawing itaway. Provision is usually made to ensure that the web W shall bearagainst the periphery of the new roll as long as possible before theadhesive passes to the web W, and for this reason, the release of thebrush 13 is controlled by a timing device which in the present case isconstituted by a cam 55 (Figures 3 and 4) fast with each of the bungs43, the cam operating on a timing rod 56 to control in any usual waytherelease of the brush 13.

I claim:

1. A web supply mechanism comprising a support to carry a running webroll and a replacement web-roll, the support being movable to move therunning roll from normal running position to a replacement position andthe replacement roll to renewing and running position, a first webtensioning means to act peripherally on the roll in running position andcomprising an end less belt driven to control the tension in the webfrom the running roll and to speed up the replacement roll, means toactuate the said first tensioning means, a second web tensioning meansto operate through the centres of the rolls, electromagnetic means tooperate said second prising an electrical circuit control to transferautomatically the responsive means from the means to actuate the firsttensioning means to the electromagnetic means to render theelectromagnetic means for the running roll active in running andreplacement positions and to render the electromagnetic means for thereplacement roll inactive in the running position while the replacementroll is speeded up.

2. Mechanism as claimed in claim 1 and wherein the electrical circuitcontrol is arranged to operate fully the electromagnetic means for therunning roll independently of the responsive means when the renewingoperation has been completed.

3. Mechanism as claimed in claim 2 in which said circuit controlincludes slip ring connections between the support and theelectromagnetic means for each roll position.

References Cited in the file of this patent UNITED SKATES PATENTS1,891,965 Wood Dec. 27, 1932 2,046,048 Wood June 30, 1936 2,141,137Horton Dec. 20, 1938 2,166,737 Wood July 18, 1939 2,326,680 Ricards Aug.10, 194-3 2,502,688 Wieking Apr. 4, 1950 FOREIGN PATENTS Great BritainIan. 18, 1949

